Drastic increases in computer use have created a need to provide a platform for computer keyboards that provides various features for a computer. The platform should allow for easy access to the keyboard for use in an ergonomically correct manner, as well as allow for quick and easy storage that protects the keyboard and does not interfere with the user when the keyboard is not being used. To achieve these objectives, a plethora of keyboard platforms are commercially available. The keyboard platforms are typically secured to a bracketing mechanism that is mounted to an underside of a horizontal surface, such as a desk or a work station. The bracketing mechanism generally allows the keyboard platform to be positioned under the horizontal surface of either the desk or the work station when it is not in use. The bracketing mechanism also allows for the keyboard platform to be extended out from under the horizontal surface when a keyboard placed upon the keyboard platform is going to be used.
Bracketing mechanisms can typically adjust the height of the keyboard platform relative to the horizontal surface it is mounted to when the platform is in an extended position. This allows the user to vary the vertical positioning of the keyboard platform to a desired position while using the keyboard. It is also common for the keyboard platform to allow a small degree of tilt, so as to alter the angle of the platform supporting the keyboard rather than remain in a strictly horizontal position. Some bracketing mechanisms also allow lateral or horizontal movement in a radial direction about a pivot point located on the bracketing mechanism. However, radial rotation of the keyboard platform is of limited value because typically at least a portion of the keyboard platform will be rotated underneath the horizontal surface creating unusable space on the keyboard platform. This results because the edge of the horizontal surface is usually not aligned with the arc of rotation allowed by the bracketing mechanism. Further, the desk or work station which provides the horizontal surface may not allow the user to sit positioned perpendicular to the keyboard and the monitor in an ergonomically correct manner once the keyboard tray is radially rotated. To increase the amount of acceptable radial rotation by the keyboard platform, the bracketing mechanism would have to extend out a greater distance from the edge of the horizontal surface. This solution, however, creates stability concerns with the bracketing mechanism. As the bracketing mechanism extension increases, the bracketing mechanism can begin to exhibit undesirable bouncing or spring board type characteristics. Additionally, as the keyboard platform is moved further from the edge of the horizontal surface, maintaining a proper distance between the user and the monitor becomes difficult. Radial lateral rotation of the keyboard platform thus provides limited useful application.
Bracketing mechanisms fall into two primary types; side mount and center mount bracketing mechanisms. Side mount bracketing mechanisms typically include two arms that translate out from the horizontal surface and are connected to the keyboard tray along its sides. Center mount bracketing mechanisms typically include a single arm which translates out from the horizontal surface for connection to the keyboard tray centered on its bottom surface. Side mount, or two arm, bracketing mechanisms typically provide greater strength and stability, but also require a larger footprint for mounting to the underside of the horizontal surface (e.g., desk or table). Center mount, or single arm, bracketing mechanisms typically require a smaller footprint for mounting to the horizontal surface but can create stability problems during use when the sides of the keyboard tray deflect or teeter about the connection point between the bracketing mechanism and the keyboard platform. If the deflection of the keyboard tray can be minimized, however, center mount bracketing mechanisms can afford greater flexibility in where they are used because of their smaller mounting footprint.
Keyboard platforms also come in various sizes. There are keyboard platforms large enough to accommodate a keyboard and mouse on a single surface. Single platforms are typically 26 inches to 28 inches wide and require a clearance area of about 28 to 30 inches on the underside of the horizontal work station or desk. Work stations and desks, however, are becoming increasingly smaller, making the clearance area required to utilize the keyboard platform of greater significance. To decrease the required clearance area, two-tiered keyboard platforms that mount a smaller, separate mousing platform to a larger keyboard platform are available. The mousing platform can be secured to the keyboard platform by various techniques, such as surface mounting a bracket to either the bottom or side of the keyboard platform, surface mounting the mousing platform itself to the keyboard platform, or sandwiching a plate between the keyboard platform and a securing bracket, so that the plate can either rotate or slide out from underneath the keyboard platform to provide the mousing surface on either the left or right side. Two-tier keyboard platforms are typically more narrow than the single piece platforms and are about 18 inches to 20 inches in width. Two-tier platforms thereby increase the versatility with which they can be used by decreasing the clearance area they require.
Stability is another factor that affects the quality and performance of a keyboard platform. Stability refers primarily to deflection and damping. Deflection relates to the amount of bounce or spring experienced in the keyboard platform when the keyboard or mouse supported by the keyboard platform is used. Deflection is a greater concern for keyboard platforms secured to center mount bracketing mechanisms because of the single mounting point at the center of the keyboard platform. Keyboard platforms secured to center mount bracketing mechanisms experience the greatest deflection when weight is placed on the side areas of the keyboard platform. Damping relates to the time period it takes the keyboard platform to return to a rest position once it is deflected. It is desirable to decrease the time it takes the keyboard platform to return to its rest position and limit the time that the keyboard platform remains in a bouncing state. Weight is another consideration for the keyboard platform. The heavier a keyboard platform is, the harder it will be to initially mount to the horizontal surface or adjust its position during use once mounted. Weight may also affect the type of bracket mechanism that can be used and possibly damage either the desk, working station or other horizontal surface on which it is mounted.
Further considerations regarding a keyboard platform include durability and convenience. Keyboard platforms must be durable to withstand bumps and jars from being pushed and pulled in and out of position as well as being hit by office furniture, other equipment, the user or other office personnel. Keyboard platforms also should be convenient to use and avoid injuring the user or damaging the user's clothing.
To achieve the desired objectives, many keyboard platforms are constructed from particle board that is machined to shape and then finished with a vinyl covering added to the top and sides. A recent trend has been to utilize a phenolic resin in the construction of the board used for the keyboard platform to increase the board's strength and rigidity. Particle board keyboard platforms, while very rigid, are also heavy and tend to include sharp edges on the bottom surface that chip away over time. Particle board and phenolic resin keyboard platforms also require surface mounting any additional items or features to the keyboard platform, such as the mousing platform. Unfortunately, surface mounting items to the keyboard platform can create additional sharp edges and corners that can scratch and injure the user or snag and damage the user's clothing.
Plastic keyboard platforms have recently been introduced to overcome the weight and expense of producing particle board keyboard platforms. There are two primary types of plastic keyboard platforms. The first type uses two plastic plates that are secured together by a set of screws. The two plastic plates are approximately one-quarter to one-half inch thick. The second type of plastic keyboard platform is a single piece of plastic that is approximately two inches thick with an open bottom and a rib network that supports the top surface. Plastic keyboard platforms typically weigh less and are less expensive to produce than the particle board or phenolic resin keyboard platforms. Plastic keyboard platforms, however, continue to require surface mounting of items to the bracketing mechanism and the mousing platform which can create more sharp edges. Another drawback of plastic keyboard platforms is that they lack sufficient rigidity to prevent bouncing or deflection during use.
Deflection or bouncing of the keyboard platform affects keying and mousing accuracy achievable by the user. This in turn increases the stress level experienced by the user and causes strain on the operator's arm and shoulder as the user holds their arms up rather than resting them on the keyboard platform or mouse platform. Deflection, or bounce, can be illustrated by placing a five pound weight (which approximates the weight associated with the use of a mouse by a user's hand) on the outer edge of a keyboard platform that is secured to a bracketing mechanism mounted underneath a horizontal surface. The keyboard tray is tested when it is extended out from under the horizontal surface. The five pound weight is placed on either the left or right side along the outer edge, approximately half way between the front and back of the keyboard tray, to simulate the affect of mouse use on the keyboard tray. If the keyboard tray includes a mousing platform, then the five pound weight is placed on the outer side edge of the mousing platform. For example, a standard single arm, center mounted style of bracketing mechanism such as the Advantage Arm, Part No. 21149, offered by Weber Knapp, Co., Jamestown, N.Y., or comparable type of bracketing mechanism could be used to mount the keyboard platform to the horizontal surface. A keyboard platform of this type should preferably not deflect more than a quarter to a half of an inch at its outer edge when the five pound weight is added.
Testing different types of keyboard trays can illustrate the different qualities associated with each type of board. An AKT 100 series board manufactured by Minnesota Mining and Manufacturing Company, St. Paul, Minn. was tested, which is a vinyl covered particle board type of keyboard tray. This keyboard platform deflected approximately one half inch when a five pound weight was placed on its surface. However, the particle board keyboard platform tested weighed approximately 4.3 pounds, making it heavy and a little difficult to handle. The particle board keyboard platform also had sharp edges along its bottom surface and where the mouse platform is surface mounted to the keyboard platform.
A sheet metal type of keyboard tray manufactured by Weber Knapp Co., and identified as the 24783 Set was also tested. The sheet metal keyboard tray was thinner than the particle board keyboard tray, but weighed approximately 6.3 pounds. When the five pound weight was added, the sheet metal type keyboard tray deflected approximately one and a quarter inches at its outer edge, or beyond the desired quarter inch to half inch range. Thus, the sheet metal keyboard tray exhibited significant deflection and thus less stability than the particle board keyboard tray.
Plastic keyboard trays were also tested. The first type of plastic keyboard platform tested utilized two plastic plates secured together with a series of screws similar to the 6200 and 6400 series product lines offered by Waterloo Furniture Components Limited, Kitchener, Ontario. The actual model tested was a 6421 keyboard tray with a surface mounted pocket attached to the keyboard tray that receives and secures therein a bracket supporting the mouse platform. When a five pound weight was added, the two plastic plates secured by screws exhibited significant deflection of approximately two inches and at times the five pound weight fell off of the mousing platform altogether. The design therefore did not achieve the stability of the particle board keyboard platform or remain within the desired quarter inch to half inch level of deflection.
The second type of plastic keyboard platform tested uses a single piece of plastic and is produced by Fellowes, Itasca, Ill., as product number FEL-93810. This keyboard tray also exhibited significant deflection of approximately one and a half inches when a five pound weight was added. Additionally, the single piece of plastic included many deep ribs located on its open bottom side and had a thickness of approximately two inches to try and increase the board's stiffness. The ribs, however, also increased the number of sharp edges along the bottom of the keyboard tray as well as increased the keyboard tray's thickness, without maintaining a range of deflection within the desired quarter inch to half inch range.
There is thus no known solution to provide a stable, substantially smooth bottomed, light weight keyboard platform utilizing a central mount bracketing mechanism.